While some knives are marketed as dishwasher safe, hand washing is generally the better option. The dishwasher’s powerful spray can cause blades to bump against other utensils, dulling the edge over time. High heat and detergent may also damage wooden handles, causing them to crack, split, or loosen.
Wooden spoons, cutting boards, and other wooden utensils can absorb water during a wash cycle, leading to warping, cracking, or fading.
Best care: Wash knives and wooden utensils by hand with warm, soapy water, dry them immediately, and occasionally treat wooden handles or utensils with food-grade mineral oil to help prevent drying and cracking.
2. Crystal Glassware and Fine China
Delicate crystal glasses and fine porcelain are especially vulnerable in the dishwasher. Strong water pressure can cause fragile items to knock into one another, increasing the risk of chips or breakage. Heat and harsh detergents may also leave crystal looking cloudy and can gradually wear away decorative gold or silver accents.
Best care: Wash these items gently by hand using mild dish soap and lukewarm water. Dry with a soft, lint-free cloth to preserve their shine.
3. Cast Iron Cookware
Cast iron skillets develop a protective layer known as seasoning, which gives them their natural nonstick surface. Dishwasher detergent can strip away this seasoning, leaving the metal vulnerable to rust.
Best care: Clean cast iron by hand using hot water and a brush or non-abrasive scrubber. Dry it thoroughly and apply a light coating of cooking oil before storing.
4. Nonstick Pans
Although nonstick cookware is designed for easy cleaning, repeated dishwasher cycles can gradually wear down the nonstick coating. High temperatures and strong detergents may reduce its effectiveness over time.
Best care: Wash with a soft sponge, warm water, and mild dish soap. Avoid abrasive scrubbers and allow the pan to cool before washing to reduce the risk of warping.
5. Items with Adhesive Labels
Jars, containers, and dishes with paper labels should not go directly into the dishwasher. Heat and water can loosen the adhesive, leaving sticky residue on the item and inside the dishwasher. Pieces of paper may also clog the dishwasher’s filter.
Best care: Remove labels before washing. If they’re difficult to peel off, soak the item in warm, soapy water first and gently scrape away any remaining adhesive.
6. Insulated Travel Mugs and Thermoses
Many insulated mugs rely on a vacuum seal between two layers of stainless steel to maintain temperature. Excessive heat may damage that seal, reducing the mug’s ability to keep drinks hot or cold. Rubber gaskets and plastic lids may also wear out more quickly.
Best care: Wash insulated bottles and lids by hand with warm, soapy water. Use a bottle brush for the interior and allow everything to dry completely before reassembling.
7. Copper Cookware
Copper pots and pans require special care to maintain their polished appearance. Dishwasher detergents and heat can dull the finish, promote tarnishing, and in some cases contribute to corrosion.
Best care: Wash by hand using mild soap and warm water. Dry immediately and polish occasionally with a copper cleaner or a paste made from lemon juice and salt.
8. Antique or Valuable China
Older or hand-painted china often has delicate glazes and decorative finishes that may not withstand repeated dishwasher cycles. Even if no damage is visible after one wash, repeated exposure can gradually fade artwork and weaken the material.
Best care: Clean antique china by hand using gentle detergent and lukewarm water. Handle each piece carefully and avoid stacking heavy dishes on top.
Other Items Best Washed by Hand
Several other kitchen items are generally better kept out of the dishwasher, including:
- Aluminum cookware that may discolor.
- Wooden cutting boards and rolling pins.
- Chef’s knives and kitchen shears.
- Delicate measuring cups with printed markings.
- Certain plastic containers that aren’t labeled dishwasher safe.
- Fine serving utensils with decorative finishes.
Protecting Your Dishwasher and Kitchenware
Using the dishwasher only for items designed to withstand high heat and powerful detergents helps keep both your cookware and the appliance in better condition. Removing food residue before loading, avoiding overcrowding, and cleaning the dishwasher’s filter regularly can also improve cleaning performance and extend the machine’s lifespan.
A dishwasher is an excellent time-saver, but it’s not the right cleaning method for every item. Spending a few extra moments washing delicate cookware by hand can help preserve expensive kitchen tools, protect treasured heirlooms, and ensure they remain in excellent condition for years to come.